We propose that the energy requirement of the small for gestational age (SGA) low birth weight (LBW) infant for expenditure, digestion and storage differs from that of the appropriate for gestational age (AGA) LBW infant, due to dissimilar body composition and developmental maturity. Furthermore, because of alterations in energy expenditure and balance, the current dietary energy recommendation for the LBW infant is inappropriate for the growth retarded LBW infant.